1. Technical Field
The disclosure relates to an ultrasound transducer and an ultrasound probe for emitting ultrasound to an observation target, receiving an ultrasound echo reflected from the observation target, converting the received ultrasound echo into an echo signal, and outputting the converted signal.
2. Related Art
Ultrasound is applied in order to observe characteristics of living tissues or materials as an observation target. To be specific, the ultrasound transducer transmits the ultrasound to the observation target and receives an ultrasound echo reflected from the observation target, and the ultrasound observation apparatus can acquire information on the characteristics of the observation target by performing predetermined signal processing on the received ultrasound echo.
The ultrasound transducer includes a plurality of piezoelectric elements, each of which converts an electrical pulse signal into an ultrasound pulse (acoustic pulse) and emits the converted signal to the observation target, and further, converts the ultrasound echo reflected from the observation target into an electrical echo signal expressed by a voltage change and outputs the converted signal. For example, the ultrasound echo is acquired from the observation target by arraying the plurality of piezoelectric elements in a predetermined direction, electronically switching an element relating to transmission and reception, or causing a delay for transmission and reception of a piezoelectric body of each of the ultrasound transducers. The ultrasound transducer, which transmits the ultrasound in the one predetermined direction and acquires the ultrasound echo reflected from the observation target in this manner, is called a 1-D array ultrasound transducer.
As the ultrasound transducer, 2-D array ultrasound transducer in which a plurality of piezoelectric elements is arranged in a matrix and two directions intersecting each other are set as scanning directions has been known in addition to the above-described 1-D array type (for example, see JP 2008-245705 A). For example, the 2-D array ultrasound transducer can acquire an ultrasound echo in an elevation direction which is orthogonal to the scanning direction of the 1-D array ultrasound transducer. The 2-D array ultrasound transducer can acquire a plurality of ultrasound images (sectional images) in the elevation direction. Thus, when the ultrasound transducer is provided at a distal end portion of an endoscope and a position of a puncture needle protruding from the distal end portion of the endoscope is confirmed while examining an inside of an observation target, for example, it is possible to confirm an inclination direction of the puncture needle from the plurality of ultrasound images even if a protruding direction of the puncture needle is inclined with respect to the scanning direction.